1. Field of the Invention
The present invention relates to a power system of a clothes washing machine.
2. Description of the Related Art
Generally, a washing machine includes a main body defining an outer configuration thereof, a water tub installed within the body, and a rotating drum (spin basket) and blade mounted within the water tub. A power system for driving the rotating drum and blade is mounted under the water tub.
The power system conventionally comprises a motor, a power transmission system, and a belt for connecting the motor to the power transmission system. This will be described hereinbelow with reference to FIG. 5.
As shown in the drawing, a conventional power transmission system 10 has a hollow dehydrating or spin drying shaft 11 and a laundering shaft 12 inserted into the hollow portion of the hollow dehydrating shaft 11. The laundering shaft 12 is divided into upper and lower portions, with a planetary gear unit 13 being disposed therebetween. The planetary gear unit 13 changes a rotating speed of the power transmission system 10. A brake band 14 and a brake lever 15 are disposed beside the dehydrating shaft 11 to brake the rotation of the dehydrating shaft 11. A one-way bearing 16 cooperates with the brake band 14 for suppressing rotation of a rotating drum 20 and permitting the dehydrating shaft 11 to rotate in only one direction. The bearing is mounted on an outer circumference of the dehydrating shaft 11. In addition, a clutch spring 17 and a clutch lever 18 for transmitting/interrupting power from the motor to both the dehydrating shaft 11 and the laundering shaft 12 are mounted under the one-way bearing 16. A pulley 19 on which a belt (not shown) is engaged is mounted on a lower end of the laundering shaft 12.
In this conventional power transmission system 10, torque of the motor is selectively transmitted to a rotating agitator blade 21 or both the blade and the rotating drum 20 through the clutch spring 17, thereby performing the washing and dehydrating operations. To achieve this, it is necessary that the clutch spring 17 has a high degree of tensile strength to enable the transmission or interruption of torque from the motor to the dehydrating shaft 11 and the laundering shaft 12, both of which are rotated at a high speed. However, the manufacturing process for such a spring having high tensile strength is complicated, and, as a result, manufacturing costs are increased.
In addition, the brake band 14 for preventing the rotating drum 20 from idling during the washing operation is, when it brakes the rotating drum 20 in one direction, subjected to a relatively high force generated when the rotating drum 20 is being urged to rotate by water currents being generated. As a result, the above described one-way bearing 16 must be used, making the structure complicated and increasing manufacturing costs.
Finally, an unpleasant noise is generated during the braking operation of the brake band.
As described above, the conventional power system of a washing machine is complicated with regard to the arrangement of parts for performing the washing, dehydrating and braking operations, making it difficult to manufacture the same and increasing manufacturing costs. In addition, because of the large number of parts needed for this complicated arrangement, much space is required which, in turn, acts to increase the overall size of the washer.